Reactions of Rhenacyclobutadiene Complexes with Allenes

The reactivity of low-valent metallacyclobutadienes toward allenes was studied. Rhenacyclobutadienes of the type Re{−C(Ar)═C(CO2Et)C(OR)═}(CO)4 are unreactive toward allenes such as PhCH═C═CH2, MeO...